In the forthcoming grant period, the High Voltage Electron Microscope Facility at Boulder will continue to divide available operating time between applicants from outside the University at Boulder (extra mural users) and investigators from within the Department of MCD Biology. Greater attention will be given to the taking of stereo pairs of micrographs in recognition of the fact that only with these can much of the depth information be made available to the viewer. The techniques for the taking and display of these are under continuing investigation toward the end of making them ever more valuable. Within this period it is planned as well to digitize for computer analysis data from stereo images derived from thick serial sections. It is hoped in this way to reconstruct in isolation a number of intracellular systems which otherwise are unavailable for morphological analysis. It is planned also to complete the construction of a cold stage for the microscope that will permit the study of frozen dried specimens, thus avoiding artifacts which may arise from other methods of fixation and drying. It is expected that, as in previous years, a wealth of new ultrastructural information will emerge from the several projects brought to the instrument.